1. Field of the Invention
The present invention relates to an optical head of a high density disk driver using a near field optical system, and more particularly, to a contamination preventing device of an optical head for a near field recording by having a contamination preventing unit for preventing a collective lens of a slider from contaminating by foreign substance.
2. Description of the Background Art
With the rapid development of networks and information technology, a recording capacity of a hard disk or an auxiliary storing unit of a computer is being increased. The increase in the recording capacity is due to a necessity of a means for recording large capacity image information or data information.
In case of the hard disk, its recording capacity is increased by 60% every year contrasting with its former year. In case of an optical disk drive for a computer auxiliary memory unit, it has an information storage capacity ranging from a few gigabit to scores of gigabit.
However, the storage capacity of the current information storage unit is likely to have a limitation in view of a technological development.
Recently, a near field recording (NFR), emerging as a next-generation information storage unit, is capable of accommodating a voluminous amount of data information and is expected to be able to meet the information storage requirement in the future.
A near field optical system realizing the near field information recording technology overcomes a diffraction limitation of a far field optical system adopted to an optical disk and allows a high density recording and reproducing by using an optical fiber or a new collective lens (i.e., solid immersion lens (SIL)).
FIG. 1 is a schematic perspective view of a disk driver having a near field optical head.
With reference to FIG. 1, a driver includes a drive 10 mounting a disk therein; a spindle motor 12 rotating the disk (D) installed and mounted within the drive 10; a suspension 15 rotated by being connected to a VC motor (VCM) installed in the drive (10); an optical head 20 installed at an end portion of the suspension 15, and recording or reproducing information into or from the disk (D); and a landing plate 17 installed at one side of the drive 10, where the optical head 20 is positioned when the disk (D) is not mounted.
The optical head includes two lenses installed at a vertically penetrated collecting hole, so that when the suspension 15 is rotated upwardly of the disk (D) according to the operation of the VC motor, the optical head 20 records information into the disk (D) or reproduces information recorded in the disk (D) in a state that it is located near the disk (D) according to an aerodynamic flying force.
In detail, with reference to FIG. 2, the optical head 20 includes a slider 21 having a collecting hole 21a in the vertical direction through which light is transmitted and being installed at an end portion of the suspension 15, an objective lens 23 being installed at an upper side of the collecting hole 21a of the slider 21 and refracting incident light, and a collective lens 25 being installed at a lower side of the collecting hole 21a of the slider 21, collecting light transmitting the objective lens 23 and forming a spot at an upper surface of the disk (D).
In such an optical head 20, in a state that the slider 21 is positioned at the upper surface of the disk (D) owing to aerodynamic flying force, the incident light is much refracted as passing the objective lens 23 and the collective lens 25 and a spot below a diffraction limitation is formed on the disk (D), so that a high density recording and reproducing can be accomplished.
In such a near field optical head as described above, however, while the slider 21 is travelling over the disk (D) to perform a recording/reproducing operation of information on the disk (D), a foreign substance such as a powder possibly created due to friction of the disk (D) or a dust in the air may be introduced on the lower surface of the slider 21 according to the rotation of the disk (D).
Accordingly, as the collective lens travels over the disk over an extended period of time, the foreign substances 27 cling to the surface of the collective lens 25 of the slider 21, contaminating the collective lens 25.
As the collective lens 25 is contaminated, the light output through the collective lens 25 is degraded to cause a problem in recording/reproducing information.
Especially, compared to the conventional far field optical system, in a near field optical system, the spot formed through the collective lens 25 is formed having a diameter below a diffraction limitation of light, the contamination of the collective lens 25 has much influence on the formation of the spot.
In addition, since an evanescent wave is used in recording/reproducing, if there exist foreign substances at the movement path of light, a bad influence is made on the transfer of an optical energy.
That is, a spot of light through the collective lens is not properly formed when information is recorded, while an error occurs in detecting a recording mark when information is reproduced, which is fatally defective in recording/reproducing information.
Therefore, an object of the present invention is to provide a contamination preventing device of an optical head for near field recording that is capable of preventing contamination of a collective lens of a slider while recording/reproducing of information is performed on a disk, thereby improving recording/reproducing performance of a near field optical recording apparatus.
Another object of the present invention is to provide a simple contamination preventing device to improve a productivity of a near field optical recording apparatus.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a contamination preventing device of an optical head for near field recording including: a slider being supported by a suspension in a deck and having a collective hole vertically penetrated though which a light source is transmitted; a collective lens being installed at a lower portion of the collective hole of the slider, collecting light generated from the light source and forming a spot at an upper surface of a recording medium; and a lens contaminant removing unit removing a foreign substance clung to the collective lens.
The contamination preventing device of an optical head for near field recording may additionally include an objective lens being installed at an upper side of the collecting hole and refracting an incident light, besides the collective lens.
In the contamination preventing device of an optical head for near field recording of the present invention, the collective lens includes every kind of lenses that would allow a near field optical magnetic interaction, and especially, includes a solid immersion lens.
To achieve the above objects, there is further provided a near field recording apparatus including: a lens making light incident on a recording medium and transmitting reflected light; a head slider mounting the lens; a suspension arm connecting the head slider; a pick-up unit supporting the suspension arm; a driving unit being connected to the pick-up unit and allowing the head slider to rotate; and a deck isolating each element from outside.
In the contamination preventing device of an optical head for near field recording of the present invention, as the lens contaminant removing unit, a ultrasonic vibrator, a dust collection electrode and a lens cleaner are used.
To achieve the above objects, there is further provided a contamination preventing device of an optical head for a near field recording, including: a slider being supported by a suspension in a deck and having a collective hole vertically penetrated though which a light source is transmitted; a collective lens being installed at a lower side of the collective hole of the slider to collect light passing an objective lens and form a spot at an upper surface of the disk; and a contamination preventing unit for resonating the slider with a high frequency so as to prevent clinging of a foreign substance to the collective lens.
To achieve the above objects, there is further provided a contamination preventing device of an optical head for a near field recording, including: a slider being supported by a suspension in a deck and having a collective hole vertically penetrated though which a light source is transmitted; a collective lens being installed at a lower side of the collective hole of the slider to collect light passing an objective lens and form a spot at an upper surface of the disk; a dust collection electrode for collecting foreign substances around the slider so as to prevent contamination of the collective lens by the foreign substances.
To achieve the above objects, there is further provided a contamination preventing device of an optical head for a near field recording, including: a slider being supported by a suspension in a deck and having a collective hole vertically penetrated though which a light source is transmitted; a collective lens being installed at a lower side of the collective hole of the slider to collect light passing an objective lens and form a spot at an upper surface of the disk; and a lens cleaner being installed in the deck so as to prevent contamination of the collective lens by the foreign substances.